On Wednesday, May 27, the International Space Station took the
next step to prepare the orbiting laboratory for the future arrival of U.S.
commercial crew and cargo vehicles.
Robotics flight controllers in Mission Control Houston and
Canada detached the large Permanent Multipurpose Module (PMM), used as a supply
depot on the orbital laboratory, from the Earth-facing port of the Unity module
and robotically relocated it to the forward port of the Tranquility module.
This move cleared the Unity port for its conversion into the spare berthing
location for U.S. cargo spacecraft; the Earth-facing port on Harmony is the
primary docking location. Harmony’s space-facing port currently is the spare
berthing location for cargo vehicles, so this move frees that location to be
used in conjunction with Harmony’s forward port as the arrival locations for
commercial crew spacecraft.